CMHC Insurance Calculator

What the CMHC Insurance Calculator does

Any Canadian mortgage with less than 20% down requires default insurance — commonly called CMHC, though Sagen and Canada Guaranty offer the same product with a near-identical premium schedule. This calculator computes the exact premium your loan-to-value places you in, the provincial sales tax that applies on top of it, and what financing that premium actually costs you every month over the full amortization.

It also shows the premium at 10%, 15% and 20% down side by side on the same purchase price, so the exact dollar value of moving up a tier — or clearing the insurance requirement entirely — is visible before you decide how much to put down.

• Your exact premium rate, named by loan-to-value band
• The dollar premium amount, and the provincial sales tax on it
• The total mortgage amount once the premium is added
• The monthly payment impact of financing the premium, not just the lump sum
• Total interest paid on the premium over the full amortization — the strongest argument for a larger down payment

The key variables that move the answer — and how lenders treat them

The premium is driven almost entirely by loan-to-value, with three specific surcharges layered on top for higher-risk structures.

• Loan-to-value — the single input the base premium rate is looked up against. Crossing from one band into another (for example, from 12% down into the 10-to-14.99% band) changes the rate applied to your entire loan, not just the portion above the threshold, which makes a down payment right at a band boundary worth checking carefully.
• Amortization — a 30-year amortization adds a surcharge on top of the standard rate, because the insurer's exposure stays outstanding for longer before the loan is paid down.
• Down payment source — borrowed funds are treated as non-traditional and carry an additional surcharge, reflecting the extra leverage already present in the transaction before the mortgage is even considered.
• Purchase price — above the insured price cap, the mortgage is not insurable at any down payment level below 20%. There is no partial premium above the cap; the requirement simply becomes a hard 20% minimum.
• Province — Ontario, Quebec and Saskatchewan apply provincial sales tax directly to the premium. This tax is calculated the same way regardless of whether the premium itself is financed, and it is never eligible to be added to the mortgage.

How this is actually calculated in Canada

The loan is the purchase price minus the down payment, and loan-to-value is that loan divided by the price. If LTV is 80% or less, the premium is zero. Otherwise, the base rate is looked up from a table of LTV bands — each band from roughly 80% to 95% carries a progressively higher rate, since a smaller down payment represents more risk to the insurer.

Surcharges are added to the base rate, not applied separately: a 30-year amortization and a non-traditional down payment source each add a fixed number of percentage points on top of the base LTV rate. The total rate is then applied to the full loan amount — premium = loan × total rate — and the provincial sales tax, where it applies, is calculated on the premium itself, not on the loan.

The premium is usually added to the mortgage principal rather than paid in cash, so the total mortgage becomes loan + premium, and the payment is recalculated on that larger amount using the same semi-annual compounding used everywhere else in Canadian mortgage math. The PST, by contrast, is never eligible to be capitalised — it is a cash requirement at closing regardless of what happens to the premium itself.

• LTV = loan ÷ price; premium = 0 if LTV ≤ 80%
• Base rate by LTV band, plus +0.20% for 30-year amortization, plus a surcharge for non-traditional down payment sources
• Premium ($) = loan × total rate
• PST = premium × provincial rate — cash only, never financeable

What you get, and how lenders use these numbers to qualify you

The premium is not a side calculation — it flows directly into the mortgage amount a lender registers, and from there into every other number in the file.

• Premium rate and amount — added directly to the loan to produce the true mortgage amount, which is the figure your payment, your qualifying ratios and your stress test are all calculated against.
• PST on the premium — not part of the mortgage at all. It is a closing-day cash requirement that sits alongside land transfer tax and legal fees, and it is frequently the line item first-time buyers forget to budget for.
• Monthly payment impact — the premium's effect on GDS and TDS runs through this figure, since a larger financed principal produces a larger qualifying payment, which uses up debt service room the same as any other cost.
• Total interest on the premium — not something a lender underwrites against directly, but it is the clearest, most concrete case for a buyer to stretch toward 20% down if the timeline allows for it.

Using your results well

Compare your current down payment tier against the next one up, and against 20%, using the tier table above. The dollar gap to the next tier is often smaller than people expect, and the premium saved from clearing it is usually a meaningful multiple of that gap.

What this calculator deliberately does not do is confirm your specific insurer's current schedule at the moment you close, or account for a non-verified self-employment income schedule, which is priced differently. Premium schedules are set by the insurers and reviewed periodically — treat the figures here as the standard schedule and confirm the exact numbers with your lender or broker before relying on them for a closing budget.

• Compare your tier against the next one up before finalising your down payment
• Budget the PST separately from your down payment — it is cash, due at closing
• If self-employed without verified income, confirm your specific premium schedule with a broker
• Weigh the total interest on the premium against how long it would take to save a larger down payment
• Treat this as an estimate — confirm the exact current premium schedule with your lender before closing

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